A US woman who shot and killed her husband and two adult children before taking her own life is thought to have committed the shocking crime as a result of being ostracised from the religion she was raised in.

Every time I tell a mate I’m doing a story on cryptocurrency, they invariably ask me the same two questions: should they invest their own hard-earned money, and which cryptocurrency will get them a Lamborghini/yacht/island quickest?

Labor demands AFP investigate Bishop

Labor has demanded the Australian Federal Police investigate Speaker Bronwyn Bishop's chartering of a helicopter for a Liberal fundraiser.

In a letter to the AFP on Saturday, Labor's waste watch spokesman Pat Conroy says refusing to investigate the allegations would be "inconsistent" with the AFP's approach to allegations against former speaker Peter Slipper in 2012.

"I ask that your investigation into Ms Bishop's conduct proceed without any further delay," he wrote in the letter obtained by AAP.

The AFP declined Mr Conroy's request for an investigation on Friday.

An AFP spokeswoman said the matter would instead be investigated by the Finance Department under the Minchin protocol, "the agreed protocol for dealing with matters of this nature".

That's despite the AFP having investigated former speaker Peter Slipper in 2012 over allegations he misused taxi dockets.

At the time, a Finance Department spokesman said the Minchin protocol did not apply where an allegation was referred directly to the AFP.